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European Heart Journal. Cardiovascular... Feb 2023Myocardial fibrosis is the heart's common healing response to injury. While initially seeking to optimize the strength of diseased tissue, fibrosis can become...
Myocardial fibrosis is the heart's common healing response to injury. While initially seeking to optimize the strength of diseased tissue, fibrosis can become maladaptive, producing stiff poorly functioning and pro-arrhythmic myocardium. Different patterns of fibrosis are associated with different myocardial disease states, but the presence and quantity of fibrosis largely confer adverse prognosis. Current imaging techniques can assess the extent and pattern of myocardial scarring, but lack specificity and detect the presence of established fibrosis when the window to modify this process may have ended. For the first time, novel molecular imaging methods, including gallium-68 (68Ga)-fibroblast activation protein inhibitor positron emission tomography (68Ga-FAPI PET), may permit highly specific imaging of fibrosis activity. These approaches may facilitate earlier fibrosis detection, differentiation of active vs. end-stage disease, and assessment of both disease progression and treatment-response thereby improving patient care and clinical outcomes.
Topics: Humans; Cardiomyopathies; Myocardium; Positron-Emission Tomography; Fibrosis; Molecular Imaging; Positron Emission Tomography Computed Tomography
PubMed: 36575058
DOI: 10.1093/ehjci/jeac242 -
Atherosclerosis Nov 2023Asymptomatic atherosclerosis begins early in life and may progress in a sex-specific manner to become the major cause of cardiovascular morbidity and death. As... (Review)
Review
Asymptomatic atherosclerosis begins early in life and may progress in a sex-specific manner to become the major cause of cardiovascular morbidity and death. As diagnostic tools to evaluate atherosclerosis in the macrocirculation, we discuss imaging methods (in terms of computed tomography, positron emission tomography, intravascular ultrasound, magnetic resonance imaging, and optical coherence tomography), along with derived scores (Agatston, Gensini, Leaman, Syntax), and also hemodynamic indices of vascular stiffness (including flow-mediated dilation, shear stress, pulse pressure, augmentation index, arterial distensibility), assessment of plaque properties (composition, erosion, rupture), stenosis measures such as fractional flow reserve. Moreover, biomarkers including matrix metalloproteinases, vascular endothelial growth factors and miRNAs, as well as the impact of machine learning support, are described. Special attention is given to age-related aspects and sex-specific characteristics, along with clinical implications. Knowledge gaps are identified and directions for future research formulated.
Topics: Female; Humans; Male; Fractional Flow Reserve, Myocardial; Sex Characteristics; Atherosclerosis; Plaque, Atherosclerotic; Positron-Emission Tomography
PubMed: 37783644
DOI: 10.1016/j.atherosclerosis.2023.117275 -
Metallomics : Integrated Biometal... Oct 2022Non-invasive imaging techniques to dynamically map whole-body trafficking of essential metals in vivo in health and diseases are needed. Despite 62Zn having appropriate...
Non-invasive imaging techniques to dynamically map whole-body trafficking of essential metals in vivo in health and diseases are needed. Despite 62Zn having appropriate physical properties for positron emission tomography (PET) imaging (half-life, 9.3 h; positron emission, 8.2%), its complex decay via 62Cu (half-life, 10 min; positron emission, 97%) has limited its use. We aimed to develop a method to extract 62Zn from a 62Zn/62Cu generator, and to investigate its use for in vivo imaging of zinc trafficking despite its complex decay. 62Zn prepared by proton irradiation of natural copper foil was used to construct a conventional 62Zn/62Cu generator. 62Zn was eluted using trisodium citrate and used for biological experiments, compared with 64Cu in similar buffer. PET/CT imaging and ex vivo tissue radioactivity measurements were performed following intravenous injection in healthy mice. [62Zn]Zn-citrate was readily eluted from the generator with citrate buffer. PET imaging with the eluate demonstrated biodistribution similar to previous observations with the shorter-lived 63Zn (half-life 38.5 min), with significant differences compared to [64Cu]Cu-citrate, notably in pancreas (>10-fold higher at 1 h post-injection). Between 4 and 24 h, 62Zn retention in liver, pancreas, and kidney declined over time, while brain uptake increased. Like 64Cu, 62Zn showed hepatobiliary excretion from liver to intestines, unaffected by fasting. Although it offers limited reliability of scanning before 1 h post-injection, 62Zn-PET allows investigation of zinc trafficking in vivo for >24 h and hence provides a useful new tool to investigate diseases where zinc homeostasis is disrupted in preclinical models and humans.
Topics: Animals; Citrates; Copper; Copper Radioisotopes; Humans; Mice; Positron Emission Tomography Computed Tomography; Positron-Emission Tomography; Protons; Reproducibility of Results; Thiosemicarbazones; Tissue Distribution; Tomography, X-Ray Computed; Zinc; Zinc Radioisotopes
PubMed: 36201445
DOI: 10.1093/mtomcs/mfac076 -
Nuclear Medicine and Biology 2023Cell death is fundamental in health and disease and resisting cell death is a hallmark of cancer. Treatment of malignancy aims to cause cancer cell death, however... (Review)
Review
Cell death is fundamental in health and disease and resisting cell death is a hallmark of cancer. Treatment of malignancy aims to cause cancer cell death, however current clinical imaging of treatment response does not specifically image cancer cell death but assesses this indirectly either by changes in tumor size (using x-ray computed tomography) or metabolic activity (using 2-[F]fluoro-2-deoxy-glucose positron emission tomography). The ability to directly image tumor cell death soon after commencement of therapy would enable personalised response adapted approaches to cancer treatment that is presently not possible with current imaging, which is in many circumstances neither sufficiently accurate nor timely. Several cell death pathways have now been identified and characterised that present multiple potential targets for imaging cell death including externalisation of phosphatidylserine and phosphatidylethanolamine, caspase activation and La autoantigen redistribution. However, targeting one specific cell death pathway carries the risk of not detecting cell death by other pathways and it is now understood that cancer treatment induces cell death by different and sometimes multiple pathways. An alternative approach is targeting the cell death phenotype that is "agnostic" of the death pathway. Cell death phenotypes that have been targeted for cell death imaging include loss of plasma membrane integrity and dissipation of the mitochondrial membrane potential. Targeting the cell death phenotype may have the advantage of being a more sensitive and generalisable approach to cancer cell death imaging. This review describes and summarises the approaches and radiopharmaceuticals investigated for imaging cell death by targeting cell death pathways or cell death phenotype.
Topics: Humans; Fluorodeoxyglucose F18; Neoplasms; Positron-Emission Tomography; Tomography, X-Ray Computed; Radiopharmaceuticals
PubMed: 37598518
DOI: 10.1016/j.nucmedbio.2023.108380 -
The British Journal of Radiology Dec 2022Total body (TB) positron emission tomography (PET) instruments have dramatically changed the paradigm of PET clinical and research studies due to their very high... (Review)
Review
Total body (TB) positron emission tomography (PET) instruments have dramatically changed the paradigm of PET clinical and research studies due to their very high sensitivity and capability to image dynamic radiopharmaceutical distributions in the major organs of the body simultaneously. In this manuscript, we review the design of these systems and discuss general challenges and trade-offs to maximize the performance gains of current TB-PET systems. We then describe new concepts and technology that may impact future TB-PET systems. The manuscript summarizes what has been learned from the initial sites with TB-PET and explores potential research and clinical applications of TB-PET. The current generation of TB-PET systems range in axial field-of-view (AFOV) from 1 to 2 m and serve to illustrate the benefits and opportunities of a longer AFOV for various applications in PET. In only a few years of use these new TB-PET systems have shown that they will play an important role in expanding the field of molecular imaging and benefiting clinical practice.
Topics: Humans; Tomography, X-Ray Computed; Positron-Emission Tomography; Radiopharmaceuticals; Molecular Imaging
PubMed: 35993615
DOI: 10.1259/bjr.20220357 -
Medical Physics Oct 2021To investigate the relationship between macrovasculature features and the standardized uptake value (SUV) of positron emission tomography (PET), which is a surrogate for...
PURPOSE
To investigate the relationship between macrovasculature features and the standardized uptake value (SUV) of positron emission tomography (PET), which is a surrogate for the metabolic activity of a lung tumor.
METHODS
We retrospectively analyzed a cohort of 90 lung cancer patients who had both chest CT and PET-CT examinations before receiving cancer treatment. The SUVs in the medical reports were used. We quantified three macrovasculature features depicted on CT images (i.e., vessel number, vessel volume, and vessel tortuosity) and several tumor features (i.e., volume, maximum diameter, mean diameter, surface area, and density). Tumor size (e.g., volume) was used as a covariate to adjust for possible confounding factors. Backward stepwise multiple regression analysis was performed to develop a model for predicting PET SUV from the relevant image features. The Bonferroni correction was used for multiple comparisons.
RESULTS
PET SUV was positively correlated with vessel volume (R = 0.44, p < 0.001) and vessel number (R = 0.44, p < 0.001) but not with vessel tortuosity (R = 0.124, p > 0.05). After adjusting for tumor size, PET SUV was significantly correlated with vessel tortuosity (R = 0.299, p = 0.004) and vessel number (R = 0.224, p = 0.035), but only marginally correlated with vessel volume (R = 0.187, p = 0.079). The multiple regression model showed a performance with an R-Squared of 0.391 and an adjusted R-Squared of 0.355 (p < 0.001).
CONCLUSIONS
Our investigations demonstrate the potential relationship between macrovasculature and PET SUV and suggest the possibility of inferring the metabolic activity of a lung tumor from chest CT images.
Topics: Fluorodeoxyglucose F18; Humans; Lung Neoplasms; Positron Emission Tomography Computed Tomography; Positron-Emission Tomography; Retrospective Studies
PubMed: 34382221
DOI: 10.1002/mp.15158 -
International Journal of Molecular... Dec 2022Fibromyalgia (FM) represents a condition that is still controversial in its entity, pathophysiology, diagnosis and management. The aim of this review is to focus on... (Review)
Review
Fibromyalgia (FM) represents a condition that is still controversial in its entity, pathophysiology, diagnosis and management. The aim of this review is to focus on imaging aspects of FM, especially on novel approaches in molecular imaging, with a special focus on neuroimaging. Novel functional and molecular imaging findings may represent, eventually, future biomarkers both in research settings and in terms of clinical practice. Several imaging techniques have already been tested in clinical trials in the FM field, including functional MRI, positron emission tomography (PET) imaging with F-FDG in FM, PET imaging of the dopaminergic system, PET imaging of the GABAergic system, PET imaging with neuroinflammation and neuroimmune parameters, PET imaging of the opioid system and HO-PET activation studies. Therefore, the potential role in the FM field of fMRI and different PET tracers has been discussed in different settings, serving as a comprehensive guide of novel imaging options both in research and in the clinical field.
Topics: Humans; Fibromyalgia; Neuroimaging; Positron-Emission Tomography; Fluorodeoxyglucose F18; Magnetic Resonance Imaging; Molecular Imaging
PubMed: 36555158
DOI: 10.3390/ijms232415519 -
The British Journal of Radiology Aug 2019The myocardium and the cardiovascular system are often involved in patients with sarcoidosis. As therapy should be started as early as possible to avoid complications... (Review)
Review
The myocardium and the cardiovascular system are often involved in patients with sarcoidosis. As therapy should be started as early as possible to avoid complications such as left ventricular dysfunction, a prompt and reliable diagnosis by means of non-invasive tests would be highly warranted. Among other techniques, F-fluorodeoxyglucose (FDG) positron emission tomography (PET) has emerged as a high sensitive tool to detect sites of inflammation before morphological changes are visible to conventional imaging techniques. We therefore aim at summarizing the most relevant findings in the literature on the use of F-fluorodeoxyglucose PET in the diagnostic workup of cardiac sarcoidosis and to underline future perspectives.
Topics: Cardiomyopathies; Fluorodeoxyglucose F18; Heart; Humans; Positron-Emission Tomography; Radiopharmaceuticals; Sarcoidosis
PubMed: 31166768
DOI: 10.1259/bjr.20190247 -
Annals of Oncology : Official Journal... Jan 2022
Topics: Humans; Immunotherapy; Neoplasms; Positron-Emission Tomography
PubMed: 34808339
DOI: 10.1016/j.annonc.2021.11.003 -
Revista Medica de Chile Feb 202218F-fluorodesoxyglucose positron emission tomography/ computed tomography (PET-CT) has a high sensitivity and specificity to detect medullary and extramedullary lesions...
BACKGROUND
18F-fluorodesoxyglucose positron emission tomography/ computed tomography (PET-CT) has a high sensitivity and specificity to detect medullary and extramedullary lesions in multiple myeloma (MM).
AIM
To describe the findings of PET-CT in extramedullary multiple myeloma (EMM) at diagnosis and at relapse, and correlate its results with clinical variables, response to treatment and survival.
MATERIALS AND METHODS
Review of medical records and PET-CT reports of 39 patients with multiple myeloma (MM) who had at least one PET-CT study, treated between January 1, 2015, and January 1, 2019 at a clinical hospital.
RESULTS
The Standard Uptake Values for each hypermetabolic lesion were not described in PET-CT reports. Fifteen patients had an EMM and in eight, without a previous clinical suspicion, PET-TC lead to the diagnosis. The mortality rate in the 39 patients with MM was 46%. Sixty seven percent of deaths occurred in patients with EMM.
CONCLUSIONS
PET-TC was useful to diagnose EMM. However, a standardization in PETCT reports would be required to unify criteria. As previously reported, EMM had a greater aggressiveness and lower survival.
Topics: Fluorodeoxyglucose F18; Humans; Multiple Myeloma; Neoplasm Recurrence, Local; Positron Emission Tomography Computed Tomography; Positron-Emission Tomography; Radiopharmaceuticals
PubMed: 36156646
DOI: 10.4067/S0034-98872022000200199